/**
 * Creat with IntelliJ IDEA
 * Description:
 * User:WZW
 * Date:2021-11-27
 * Time:20:14
 */
class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}
public class Solution {
    public ListNode Merge(ListNode list1, ListNode list2) {
        if (list1 == null) {
            return list2;
        } else if (list2 == null) {
            return list1;
        }
        ListNode head = new ListNode(-1);
        ListNode cur = head;
        while (list1 != null && list2 != null) {
            if (list1.val < list2.val) {
                cur.next = list1;
                list1 = list1.next;
            } else {
                cur.next = list2;
                list2 = list2.next;
            }
            cur = cur.next;
        }
        if (list1 == null) {
            cur.next = list2;
        } else if (list2 == null) {
            cur.next = list1;
        }
        return head.next;
    }

    public static void main(String[] args) {
        System.out.println("good!");
    }
}

